#26Ex-Proof / ATEX & IECEx Hazardous Area Electrical Inspection
Multi-Asset / Multi-Point Equipment Schedule
Inspect multiple transformers, panels, rooms, motors, or RCDs in this module without overwriting previous assets. Each item receives a permanent QR Sticker UID preserved across annual audits.
Sticker UID: OC-EXP0-2B35Standard Limits, Equations & Space Presets
IEC 60079-14 (Design & Erection) and IEC 60079-17 (Inspection & Maintenance) Explosive Atmospheres compliance engine: Zone vs Equipment Protection Level (EPL), Gas/Dust Group hierarchy (IIA/IIB/IIC & IIIA/IIIB/IIIC), Temperature Class (T1-T6) vs Auto-Ignition Temperature, Intrinsic Safety (Ex i) loop parameters, and Ex e motor tE time.
T_class_max <= T_AIT (Gas) | T_surface <= (2/3) x T_cloud (Dust)
Maximum equipment surface temperature must not exceed the auto-ignition temperature of the explosive atmosphere (IEC 60079-14 §5.6).
Uo <= Ui, Io <= Ii, Po <= Pi, (Ci + C_cable) <= Co, (Li + L_cable) <= Lo
Intrinsic Safety (Ex ia / Ex ib) entity parameter verification between safety barrier and field instrument (IEC 60079-14 §16.2).
IEC 60079-14 Table 1 & Table 2: Hazardous Zone, EPL, Gas Group & Temperature Class Matrix
IEC 60079-14 / ATEX Directive 2014/34/EU| Hazardous Zone | Permitted EPLs | Typical Protection Concepts (Ex) | Gas / Dust Group Hierarchy |
|---|---|---|---|
| Zone 0 (Gas continuous) | Ga only | Ex ia, Ex ma, Ex da | IIC covers IIB & IIA | IIB covers IIA |
| Zone 1 (Gas intermittent) | Ga or Gb | Ex d (Flameproof), Ex e (Increased Safety), Ex ib, Ex px, Ex mb, Ex q | IIC (H2, C2H2) > IIB (C2H4) > IIA (Propane, CH4) |
| Zone 2 (Gas abnormal) | Ga, Gb, or Gc | Ex ec, Ex nA, Ex nR, Ex ic, Ex pz (plus all Zone 0/1 types) | IIC > IIB > IIA |
| Zone 20 (Dust continuous) | Da only | Ex ta, Ex iaD, Ex maD | IIIC (Conductive dust) covers IIIB & IIIA |
| Zone 21 (Dust intermittent) | Da or Db | Ex tb, Ex ibD, Ex mbD, Ex pxD | IIIB (Non-conductive dust) covers IIIA (Flyings) |
| Zone 22 (Dust abnormal) | Da, Db, or Dc | Ex tc, Ex icD, Ex pzD | IIIC > IIIB > IIIA |
IEC 60079-0 Temperature Classes (T1 - T6) for Group II Electrical Equipment
IEC 60079-0 §5.3.2.2| Temperature Class | Max Surface Temp (°C) | Permitted if Gas AIT > | Typical Representative Gases / Vapours |
|---|---|---|---|
| T1 | 450 °C | > 450 °C | Hydrogen (560°C), Methane (537°C), Ammonia (630°C), Propane (470°C) |
| T2 | 300 °C | > 300 °C | Acetylene (305°C), Ethylene (425°C), Ethanol (363°C), n-Butane (365°C) |
| T3 | 200 °C | > 200 °C | Petrol / Gasoline (220-280°C), Diesel / Jet Fuel (210°C), Hydrogen Sulphide (260°C) |
| T4 | 135 °C | > 135 °C | Acetaldehyde (140°C), Diethyl Ether (160°C) |
| T5 | 100 °C | > 100 °C | Special reactive chemical intermediates |
| T6 | 85 °C | > 85 °C | Carbon Disulphide CS2 (95°C), Ethyl Nitrite (90°C) |
Measured Inputs
IEC 60079 Zone/EPL Matrix, Gas Group, T-Class & Intrinsic Safety Verification
Deterministic ATEX (2014/34/EU) & IEC 60079-14 / 60079-17 compliance engine: verifies Equipment Protection Level (EPL Ga/Gb/Gc & Da/Db/Dc) against Hazardous Zone (0/1/2 & 20/21/22), Gas/Dust Group hierarchy (IIC > IIB > IIA), Temperature Class (T1-T6) vs Auto-Ignition Temperature (AIT), Intrinsic Safety (Ex i) loop parameters (Uo <= Ui, C_cable <= Co), and Ex e motor tE time.
Pending / Not tested — results stay neutral until valid measured values are entered.
- Pending
Hazardous Zone vs Equipment Protection Level (EPL)
Gb in Zone 1
Acceptance: Zone 0 -> Ga; Zone 1 -> Ga/Gb; Zone 2 -> Ga/Gb/Gc; Zone 20 -> Da; Zone 21 -> Da/Db; Zone 22 -> Da/Db/Dc [IEC 60079-14:2013 Table 1 / ATEX 2014/34/EU]
- Pending
Gas / Dust Subdivision Hierarchy Compatibility
Equipment IIB vs Site Requirement IIA
Acceptance: Gas: IIC covers IIB & IIA; IIB covers IIA. Dust: IIIC covers IIIB & IIIA (Gas and Dust groups are not interchangeable) [IEC 60079-14 §5.5 / IEC 60079-0]
- Pending
Temperature Class (T4 <= 135 degC) vs Auto-Ignition Temp
-
Not tested - enter the measured value. Acceptance: Max surface temperature <= Gas Auto-Ignition Temperature T_AIT [IEC 60079-14 §5.6.2] [IEC 60079-14 §5.6]
- Pending
Hazardous Area Equipotential Bonding Continuity
- Ohm
Not tested - enter the measured value. Acceptance: Metallic enclosure, cable gland armor, and pipework bonding continuity to earth bar <= 0.20 Ohm [IEC 60079-14 §6.3 / IEC 60079-17]
- Pending
Ex e Motor Locked-Rotor Protection Time tE
- s
Not tested - enter the measured value. Acceptance: tE >= 5.0 s and inverse thermal overload device must trip from cold/hot before tE is reached at IA/IN [IEC 60079-7 / IEC 60079-14 §11.3]
- Pending
Intrinsic Safety (Ex i) Loop Entity Verification (Uo <= Ui & Cc <= Co)
-
Not tested - enter the measured value. Acceptance: Safety barrier Uo <= instrument Ui, Io <= Ii, Po <= Pi, and total capacitance (Ci + C_cable) <= Co [IEC 60079-14 §16.2 / IEC 60079-25]
Verification Checklist (0 / 22)
1Explosion Protection Document (EPD) and Hazardous Area Classification drawing (Zone 0/1/2, 20/21/22) available and current [IEC 60079-10]
2ATEX / IECEx certificate numbers on equipment nameplates match the hazardous area equipment register [IEC 60079-17 Table 1 A1]
3Equipment Protection Level (EPL Ga/Gb/Gc or Da/Db/Dc) and Ex protection concept match the classified Zone
4Equipment Gas/Dust Group (IIA/IIB/IIC or IIIA/IIIB/IIIC) and Temperature Class (T1-T6) verified for all present substances
5Special conditions of safe use ('X' suffix on certificate) verified and implemented on site
6Ambient temperature range on nameplate (default -20 degC to +40 degC unless marked) suitable for local environment
7Ex d flameproof enclosure flange gaps free of corrosion, paint, non-setting grease alterations, or unauthorized gaskets [IEC 60079-14 §10]
8All Ex d enclosure cover bolts present, of correct property class (e.g. A2-70 / 8.8), and tightened to OEM torque
9Ex d barrier cable glands (compound-filled) or certified elastomer compression glands installed per IEC 60079-14 §10.6.2 selection chart
10Minimum 5 full threads engaged on parallel/tapered NPT/Metric Ex d cable gland entries and locknuts/IP washers fitted
11All unused cable entries sealed with ATEX/IECEx certified Ex d / Ex e stopping plugs (no plastic transit plugs left in place!)
12Minimum clearance around Ex d flamepath joints maintained (>= 10 mm IIA, >= 30 mm IIB, >= 40 mm IIC) [IEC 60079-14 Table 13]
13Ex e increased safety terminal boxes free of moisture; IP54 minimum ingress protection gasket intact and only 1 conductor per terminal clamp
14Ex e rotating machines protected by current-dependent thermal overload relay calibrated to trip within tE at starting ratio IA/IN (plus PTC thermistor)
15VFD-fed Ex motors type-tested together with converter or equipped with certified direct winding temperature protection [IEC 60079-14 §11.3.4]
16Ex i (Intrinsic Safety) circuits clearly identified with light-blue cables/terminals and segregated >= 50 mm from non-IS power cables
17Ex i Zener barriers earthed via dedicated high-integrity insulated copper conductor (>= 4 mm2) with impedance < 1.0 Ohm to main earth
18Ex i descriptive system document (loop calculation verifying Uo<=Ui, Io<=Ii, Po<=Pi, Co>=Ci+Cc, Lo>=Li+Lc) on file [IEC 60079-25]
19Supplementary equipotential bonding connected to all exposed and extraneous conductive parts (cable armour, trays, process pipes <= 0.2 Ohm)
20Anti-static surface resistance verified on non-metallic enclosures/fan blades to prevent electrostatic charge accumulation [IEC 60079-0 §7.4]
21No unauthorized hot-work or live electrical opening permitted without a gas-free certificate / PTW
22Periodic IEC 60079-17 inspection grade (Visual / Close / Detailed) and maximum 3-year interval logged and signed by CompEx/certified engineer
General Notes
Free plan: 5 of 5 inspections / calculations left this month.